Sunday, December 8, 2013

New VHF Antenna

I installed a new VHF antenna this weekend.  Still up in a temporary stand,  but I am now using it.

My major problem is that I feel deaf.  People say they can hear me fine, but I just can't hear them.  So though was to try a larger antenna.  Mounted it on a 10' long piece of chain link fence top rail.  So the bottom of the antenna is at 10' and the top at 26'.

This is a Jetstream JTB1B.   It is a collinear antenna   3x5/8 on 2m and 8x5/8 on 70cm.  It is about 16 feet long.   Gain is claimed to be 8.3db on 2m an 11.7db on 70cm.   Testing it with a SWR meter, it is showing 1.2:1 or better at 50watts on 146.520mhz .  Can't beat that.

So how does it compare to the TRAM 1480 8 foot long antenna I have been using.

My current method is watching the built in meter on the radio on the NWS stations in the area.  Not quite 2m, but the only thing close to a beacon I can think of.
So  the results are using same cables, tests within 15min of each other:

Station   Freq     Tram   Jetstream
1         162.550     2         4-6
2         162.500     9+        9+
3         162.475     4          9
4         162.425     4          6-8
5         162.450     0          2
6         162.500     4-6       6-8
7         162.525     6-8       6-8


So what does it look like:

So compared to the Tram 1480 the antenna is twice as long.  Mounted at 10' as opposed to 16'  and is pulling in way more signal.  This seems to be an improvement.   Will run this setup for a week and if it continues to work well, will mount it permanently.

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